Transcultural Adaptation and Validation of the German DIGEST-FEES.

INTRODUCTION

Flexible Endoscopic Evaluation of Swallowing (FEES) is one of two diagnostic gold standards for pharyngeal dysphagia in patients with head and neck cancer (HNC). However, an evidence-based summary outcome measure was missing until recently. The Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) for FEES was adapted from DIGESTV2 for videofluoroscopy for this purpose and is a validated analysis method, grading the severity of pharyngeal dysphagia based on the swallowing parameters safety and efficiency. Main aim of this study was to translate and validate DIGEST-FEES into German (DIGEST-FEES-G).

METHODS

First, the transcultural translation included forward and backward translations, cognitive interviews, and consensus in an expert committee together with the original developers. Subsequently, the 100 endoscopic examination videos of the DIGEST-FEES original validation study were retrospectively analyzed with DIGEST-FEES-G.

RESULTS

After a training phase, inter-rater reliability was almost perfect for overall DIGEST-FEES-G grade (Kw = 0.89), DIGEST-FEES-G-safety (Kw = 0.9) and DIGEST-FEES-G-efficiency (Kw = 0.88). Intra-rater reliability for the DIGEST-FEES-G rating was almost perfect (rater 1: Kw = 0.81-0.88) and substantial to almost perfect (rater 2: Kw = 0.78-0.92). Overall DIGEST-FEES-G grade correlated with the German Murray Secretion Scale (r = 0.47; p < 0.01), German Yale Vallecular Residue (r = 0.74; p < 19 0.01) and German Yale Pyriform Sinus Residue (r = 0.66; p < 0.01).

CONCLUSION

The validation and reliability findings of the original study could be replicated for DIGEST-FEES-G which increases validity of the DIGEST-FEES scale. The translated version, DIGEST-FEES-G, provides a psychometrically sound analysis method for the severity grading of pharyngeal dysphagia in HNC for German-speaking practitioners.